| Topic/Section | Key finding (with key numbers) | Population/Setting | Year | Source (first author, journal) | PMID if available | URL |
|---|---|---|---|---|---|---|
| Surveillance / epidemiology | U.S. confirmed AFM cases: 238 in 2018; then 47 (2019), 33 (2020), 28 (2021), 47 (2022). Confirmed AFM requires acute flaccid limb weakness plus MRI spinal cord lesion largely restricted to gray matter spanning ≥1 vertebral segment. 2018 cases were 94% aged <18 years; median age 5.3 years. ICU admission 54%, respiratory support 27%, mechanical ventilation 23%. EV-D68 detected in 37 cases in 2018; lower in later years. (pqac-00000001, pqac-00000000, pqac-00000006) | United States national AFM surveillance, 2018–2022 | 2024 | Whitehouse, MMWR |  | https://www.cdc.gov/mmwr/volumes/73/ss/ss7304a1.htm |
| Clinical characteristics | Among 238 confirmed AFM patients in 2018, median age was 5.3 years; 86% had onset during Aug–Nov; 92% had prodromal fever/respiratory illness beginning median 6 days before weakness; common findings: gait difficulty 52%, neck/back pain 47%, limb pain 34%; 98% hospitalized, 54% ICU, 23% intubated/mechanically ventilated. (pqac-00000004) | United States confirmed AFM patients during 2018 peak year | 2020 | Kidd, MMWR |  | https://doi.org/10.15585/mmwr.mm6931e3 |
| Recent surveillance development | Multimodal Colorado EV-D68/AFM surveillance combined syndromic, clinical PCR, and wastewater data. From Jun 15–Nov 3, 2022, 529 EV/RV-positive respiratory specimens were tested and 121/529 (22.9%) were EV-D68-positive; peak weekly positivity 78.6% in late Aug 2022. Wastewater detection preceded the syndromic alarm by ~1 month/1–2 weeks depending on analytic layer. Colorado had 4 suspected AFM cases in 2022 versus 17 in 2018. (pqac-00000008, pqac-00000009, pqac-00000011) | Colorado, USA pediatric hospital/public-health surveillance during 2022 EV-D68 outbreak | 2024 | Messacar, Emerging Infectious Diseases |  | https://doi.org/10.3201/eid3003.231223 |
| Etiology / overall review | AFM is strongly associated with non-polio enteroviruses, especially EV-D68; direct virus detection in CSF is uncommon, but epidemiology, animal models, and CSF antibody studies support causality. Long-term recovery is often incomplete with residual weakness, atrophy, and neurologic/musculoskeletal sequelae; rehabilitation and selected nerve-transfer surgery may improve function. (pqac-00000002) | International review of human clinical, laboratory, and model-organism evidence | 2021 | Murphy, The Lancet |  | https://doi.org/10.1016/S0140-6736(20)32723-9 |
| Rehabilitation / outcomes | AFM rehab review notes electrodiagnostics usually show motor neuronopathy/neuropathy with preserved sensory conduction. Recovery is often poor; some series reported full recovery in only 10% or 41%. Greatest recovery generally occurs within 12 months, but gains may continue to 18 months. Supportive multidisciplinary rehab, ABRT, ventilatory management, diaphragmatic pacing, and nerve transfer surgery are discussed. (pqac-00000005) | Rehabilitation literature and AFM cohorts, largely pediatric | 2021 | Ide, PM&R Clinics of North America |  | https://doi.org/10.1016/j.pmr.2021.02.004 |
| Novel rehabilitation intervention | In a 4-patient pediatric case series, 22 sessions over 5–8 weeks of transcutaneous spinal cord stimulation (TSS) plus gait training were feasible and safe. Session completion was 98.48%; no significant adverse events. 6MWT improved by +98.3 m, +68 m, +9.4 m, and +49.4 m; 3/4 exceeded MCID. WISCI-II improved clinically in 2/4 participants. (pqac-00000012, pqac-00000013, pqac-00000014) | Four children with incomplete SCI secondary to AFM | 2024 | Neighbors, Children |  | https://doi.org/10.3390/children11091116 |
| Surgical reconstruction / prognosis | Retrospective cohort of 39 AFM patients (50 upper extremities). Recovery assessed at median 3, 6, and 37 months. Key prognostic result: none of the patients with M0 shoulder abduction at 6 months later recovered M1 or better. Twenty-seven patients (29 extremities) underwent reconstruction (nerve transfer, muscle-tendon transfer, free muscle transfer). Elbow/hand outcomes were more consistent than shoulder outcomes. (pqac-00000017, pqac-00000020, pqac-00000023) | AFM upper-extremity paralysis, 2011–2019 surgical referral cohort | 2024 | Doi, JBJS Open Access |  | https://doi.org/10.2106/JBJS.OA.23.00143 |
| Case report / diagnostic illustration | First reported Belgium AFM case linked to EV-D68: 4-year-old with acute right upper-limb palsy. MRI showed central gray matter T2 hyperintensity in cervical cord C2–C7 with posterior brainstem involvement; nasopharyngeal PCR positive for EV-D68; CSF enterovirus PCR negative. Authors note poor functional prognosis and no evidence-based treatment guideline. (pqac-00000025, pqac-00000026) | Single pediatric case, Belgium | 2024 | Rodesch, Case Reports in Neurology |  | https://doi.org/10.1159/000535316 |
| Prospective follow-up study / trial registry | ClinicalTrials.gov follow-up study of pediatric AFM associated with EV-D68 planned functional follow-up using Hammersmith Functional Motor Scale at 1–3 years; secondary outcomes include MRC scores, ACTIVLIM, PedsQL, ICU/mechanical ventilation duration, deaths, and complete recovery. Enrollment target 40; start date 2018-04-09. (pqac-00000032) | European children <18 years with AFM, EV-D68 PCR positivity, MRI-confirmed myelitis | 2018 | Pfeiffer, ClinicalTrials.gov (NCT03499366) |  | https://clinicaltrials.gov/study/NCT03499366 |


*Table: This table summarizes high-yield evidence on acute flaccid myelitis across surveillance, etiology, diagnostics, rehabilitation, surgery, and follow-up research. It is designed to support a disease knowledge base entry with recent statistics, clinically actionable findings, and source links.*